Flutter can't render an Expanded Widget inside a SingleChildScrollView - flutter

Question

So i have this build method:
#override
Widget build(BuildContext context) {
return Scaffold(
body: _createBody(),
);
}
Widget _createBody(){
return SafeArea(
child: Column(
children: [
Container(
margin: const EdgeInsets.only(top: 5, left: 10, right: 10),
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(
"xOrder HD",
style: TextStyle(
color: Colors.blue[900],
fontSize: 36
),
),
Container(
padding: const EdgeInsets.only(left: 13, top: 13),
alignment: Alignment.bottomLeft,
child: Text(AppVersion.xOrderVersion()),
)
],
)
),
Container(
margin: const EdgeInsets.symmetric(horizontal: 10),
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.solutionFor,
textAlign: TextAlign.start,
),
],
)
),
Expanded(
child: Container(
margin: const EdgeInsets.only(left: 25, right: 25, top: 20, bottom: 10),
child: Row(
children: [
Expanded(
child: Container(
child: Column(
children: [
Container(
padding: const EdgeInsets.symmetric(vertical: 10),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.companyList,
style: const TextStyle(
color: Colors.white,
fontSize: 16,
fontWeight: FontWeight.bold,
)
),
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.only(topLeft: Radius.circular(4), topRight: Radius.circular(4))
),
),
_loadedAziende.isEmpty ?
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.noCompanyFound,
style: const TextStyle(
color: Colors.black54,
fontSize: 16
)
),
const SizedBox(height: 50,),
GestureDetector(
onTap: () {
Navigator.push(context, MaterialPageRoute(builder: (context) => QrCodeScanner(delegate: this,)));
},
child: Material(
elevation: 5,
borderRadius: const BorderRadius.all(Radius.circular(5)),
child: Container(
padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 10),
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
const Icon(Icons.add, color: Colors.white,),
const SizedBox(width: 10,),
Text(
AppLocalizations.of(context)!.newCompany,
style: const TextStyle(
fontSize: 16,
fontWeight: FontWeight.bold,
color: Colors.white,
)
),
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.all(Radius.circular(5))
),
),
)
)
],
)
)
:
Expanded(
child: Stack(
children: [
ListView.separated(
itemCount: _aziendeToShow.length,
itemBuilder: (ctx, index) {
return InfoCell(
info: _aziendeToShow[index],
delegate: this,
);
},
separatorBuilder: (ctx, index) => const Divider(height: 1,),
),
Positioned(
bottom: 15,
right: 15,
child: GestureDetector(
onTap: () {
Navigator.push(context, MaterialPageRoute(builder: (context) => QrCodeScanner(delegate: this,)));
},
child: Container(
padding: const EdgeInsets.all(10),
child: const Icon(Icons.qr_code_scanner, color: Colors.white, size: 28),
decoration: BoxDecoration(
color: mainColor,
shape: BoxShape.circle
),
)
)
)
],
)
)
],
),
decoration: BoxDecoration(
color: Colors.grey[100],
border: Border.all(color: Colors.grey[500]!),
borderRadius: const BorderRadius.all(Radius.circular(5))
),
),
),
if(_loadedAziende.isNotEmpty)
const SizedBox(width: 25,),
if(_loadedAziende.isNotEmpty)
Expanded(
child: Container(
child: Column(
children: [
Container(
padding: const EdgeInsets.symmetric(vertical: 10),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.login,
style: const TextStyle(
color: Colors.white,
fontSize: 16,
fontWeight: FontWeight.bold,
)
),
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.only(topLeft: Radius.circular(4), topRight: Radius.circular(4))
),
),
isEmptyOrNull(_selectedAzienda) ?
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.selectAcompany,
style: const TextStyle(
color: Colors.black54,
fontSize: 16
)
),
],
)
)
:
Expanded(
child: Column(
children: [
Container(
height: 150,
margin: const EdgeInsets.symmetric(vertical: 20, horizontal: 10),
decoration: BoxDecoration(
shape: BoxShape.circle,
border: Border.all(color: Colors.grey[400]!),
image: DecorationImage(
image: Image.network(_selectedAzienda!.aziendaLogo).image,
fit: BoxFit.contain
)
),
),
Text(
_selectedAzienda!.aziendaCode,
style: const TextStyle(
color: Colors.black,
fontSize: 25,
fontWeight: FontWeight.bold
),
),
Container(
margin: const EdgeInsets.symmetric(vertical: 30, horizontal: 15),
child: const TextField(
decoration: InputDecoration(
filled: true,
fillColor: Colors.white,
icon: Icon(Icons.person),
border: OutlineInputBorder(),
labelText: 'Username',
),
)
),
Container(
margin: const EdgeInsets.only(bottom: 30, left: 15, right: 15),
child: const TextField(
obscureText: true,
decoration: InputDecoration(
filled: true,
fillColor: Colors.white,
icon: Icon(Icons.password),
border: OutlineInputBorder(),
labelText: 'Password',
),
)
),
const Spacer(),
Container(
margin: const EdgeInsets.symmetric(vertical: 15, horizontal: 15),
padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 15),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
const Icon(Icons.login, color: Colors.white,),
const SizedBox(width: 15,),
Text(
AppLocalizations.of(context)!.login,
style: const TextStyle(
fontSize: 22,
color: Colors.white,
fontWeight: FontWeight.bold
),
)
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.all(Radius.circular(5))
),
)
],
)
)
],
),
decoration: BoxDecoration(
color: Colors.grey[100],
border: Border.all(color: Colors.grey[500]!),
borderRadius: const BorderRadius.all(Radius.circular(5))
)
),
)
],
),
),
),
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: [
Container(
margin: const EdgeInsets.all(10),
height: 82,
width: 135,
decoration: BoxDecoration(
image: DecorationImage(
image: Image.asset("assets/images/logo-axentya-inv.png").image,
fit: BoxFit.fill
)
),
)
],
)
],
),
);
}
And this is the final result:
The problem presents when i click on the TextField and the keyboard shows up going above the TextFields and showing up the black and yellow banner:
I don't know why in this screenshot the keyboard doesn't show up, but i swear that is opened.
If i try to put the main Column container inside a SingleChildScrollView, the compiler tells me it cannot render it cause I'm not specifying the height dimensions.
How should i fix this.

Answer 1

You cannot use Expanded inside SingleChildScrollView. However, you can use CustomScrollView along with SliverFillRemaining widget to achieve that:
class TestPage extends StatelessWidget {
const TestPage({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
body: CustomScrollView(
slivers: [
SliverFillRemaining(
hasScrollBody: true,
child: _createBody(),
)
],
),
);
}
Widget _createBody(){
return SafeArea(
child: Column(
children: [
Container(
margin: const EdgeInsets.only(top: 5, left: 10, right: 10),
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(
"xOrder HD",
style: TextStyle(
color: Colors.blue[900],
fontSize: 36
),
),
Container(
padding: const EdgeInsets.only(left: 13, top: 13),
alignment: Alignment.bottomLeft,
child: Text(AppVersion.xOrderVersion()),
)
],
)
),
Container(
margin: const EdgeInsets.symmetric(horizontal: 10),
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.solutionFor,
textAlign: TextAlign.start,
),
],
)
),
Expanded(
child: Container(
margin: const EdgeInsets.only(left: 25, right: 25, top: 20, bottom: 10),
child: Row(
children: [
Expanded(
child: Container(
child: Column(
children: [
Container(
padding: const EdgeInsets.symmetric(vertical: 10),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.companyList,
style: const TextStyle(
color: Colors.white,
fontSize: 16,
fontWeight: FontWeight.bold,
)
),
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.only(topLeft: Radius.circular(4), topRight: Radius.circular(4))
),
),
_loadedAziende.isEmpty ?
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.noCompanyFound,
style: const TextStyle(
color: Colors.black54,
fontSize: 16
)
),
const SizedBox(height: 50,),
GestureDetector(
onTap: () {
Navigator.push(context, MaterialPageRoute(builder: (context) => QrCodeScanner(delegate: this,)));
},
child: Material(
elevation: 5,
borderRadius: const BorderRadius.all(Radius.circular(5)),
child: Container(
padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 10),
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
const Icon(Icons.add, color: Colors.white,),
const SizedBox(width: 10,),
Text(
AppLocalizations.of(context)!.newCompany,
style: const TextStyle(
fontSize: 16,
fontWeight: FontWeight.bold,
color: Colors.white,
)
),
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.all(Radius.circular(5))
),
),
)
)
],
)
)
:
Expanded(
child: Stack(
children: [
ListView.separated(
itemCount: _aziendeToShow.length,
itemBuilder: (ctx, index) {
return InfoCell(
info: _aziendeToShow[index],
delegate: this,
);
},
separatorBuilder: (ctx, index) => const Divider(height: 1,),
),
Positioned(
bottom: 15,
right: 15,
child: GestureDetector(
onTap: () {
Navigator.push(context, MaterialPageRoute(builder: (context) => QrCodeScanner(delegate: this,)));
},
child: Container(
padding: const EdgeInsets.all(10),
child: const Icon(Icons.qr_code_scanner, color: Colors.white, size: 28),
decoration: BoxDecoration(
color: mainColor,
shape: BoxShape.circle
),
)
)
)
],
)
)
],
),
decoration: BoxDecoration(
color: Colors.grey[100],
border: Border.all(color: Colors.grey[500]!),
borderRadius: const BorderRadius.all(Radius.circular(5))
),
),
),
if(_loadedAziende.isNotEmpty)
const SizedBox(width: 25,),
if(_loadedAziende.isNotEmpty)
Expanded(
child: Container(
child: Column(
children: [
Container(
padding: const EdgeInsets.symmetric(vertical: 10),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.login,
style: const TextStyle(
color: Colors.white,
fontSize: 16,
fontWeight: FontWeight.bold,
)
),
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.only(topLeft: Radius.circular(4), topRight: Radius.circular(4))
),
),
isEmptyOrNull(_selectedAzienda) ?
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
AppLocalizations.of(context)!.selectAcompany,
style: const TextStyle(
color: Colors.black54,
fontSize: 16
)
),
],
)
)
:
Expanded(
child: ListView(
children: [
Container(
height: 150,
margin: const EdgeInsets.symmetric(vertical: 20, horizontal: 10),
decoration: BoxDecoration(
shape: BoxShape.circle,
border: Border.all(color: Colors.grey[400]!),
image: DecorationImage(
image: Image.network(_selectedAzienda!.aziendaLogo).image,
fit: BoxFit.contain
)
),
),
Text(
_selectedAzienda!.aziendaCode,
style: const TextStyle(
color: Colors.black,
fontSize: 25,
fontWeight: FontWeight.bold
),
),
Container(
margin: const EdgeInsets.symmetric(vertical: 30, horizontal: 15),
child: const TextField(
decoration: InputDecoration(
filled: true,
fillColor: Colors.white,
icon: Icon(Icons.person),
border: OutlineInputBorder(),
labelText: 'Username',
),
)
),
Container(
margin: const EdgeInsets.only(bottom: 30, left: 15, right: 15),
child: const TextField(
obscureText: true,
decoration: InputDecoration(
filled: true,
fillColor: Colors.white,
icon: Icon(Icons.password),
border: OutlineInputBorder(),
labelText: 'Password',
),
)
),
const Spacer(),
Container(
margin: const EdgeInsets.symmetric(vertical: 15, horizontal: 15),
padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 15),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
const Icon(Icons.login, color: Colors.white,),
const SizedBox(width: 15,),
Text(
AppLocalizations.of(context)!.login,
style: const TextStyle(
fontSize: 22,
color: Colors.white,
fontWeight: FontWeight.bold
),
)
],
),
decoration: BoxDecoration(
color: mainColor,
borderRadius: const BorderRadius.all(Radius.circular(5))
),
)
],
)
)
],
),
decoration: BoxDecoration(
color: Colors.grey[100],
border: Border.all(color: Colors.grey[500]!),
borderRadius: const BorderRadius.all(Radius.circular(5))
)
),
)
],
),
),
),
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: [
Container(
margin: const EdgeInsets.all(10),
height: 82,
width: 135,
decoration: BoxDecoration(
image: DecorationImage(
image: Image.asset("assets/images/logo-axentya-inv.png").image,
fit: BoxFit.fill
)
),
)
],
)
],
),
);
}
}

Answer 2

Add this resizeToAvoidBottomPadding: false to the Scaffold.
#override
Widget build(BuildContext context) {
return Scaffold(
resizeToAvoidBottomPadding: false,
body: _createBody(),
);
}
EDIT:
If you use de flutter_keyboard_visibility to reduce the logo image when the soft Keyboard is shown would be something like this:
import 'package:flutter_keyboard_visibility/flutter_keyboard_visibility.dart';
#override
Widget build(BuildContext context) {
return KeyboardVisibilityBuilder(builder: (context, isKeyboardVisible) {
return Scaffold(
resizeToAvoidBottomInset: false,
body: _createBody(isKeyboardVisible),
);
});
}
Widget _createBody(bool isKeyboardVisible) {
...
Expanded(
child: Column(
children: [
Container(
height: isKeyboardVisible ? 50 : 150, <<--- HERE
margin: const EdgeInsets.symmetric(
vertical: 20, horizontal: 10),
decoration: BoxDecoration(
shape: BoxShape.circle,
border:
Border.all(color: Colors.grey[400]!),
image: DecorationImage(...
),
}

Answer 3

The answer is in the error itself. When the column is inside a view that is scrollable, the column is trying to shrink-wrap its content but since you used Expanded as a child of the column it is working opposite to the column trying to shrink-wrap its children. This is causing this error because these two directives are completely opposite to each other.
As mentioned in the error logs try the following:
Consider setting mainAxisSize to MainAxisSize.min (for column) and using FlexFit.loose fits for the flexible(use Flexible rather than Expanded).